Rotary drill cutter



Mar, 27, 1923.

ATTORNEYS.

, wa W 2 m m a U i atented Mall 2?, i923.

HAROLD W. FLETCHER, HOUSTON, TEXAS, ASSIG'NGR TO HUGHES, TGCB'L CQLIPATXY, F HOUSTON, TEXAS, A GOEFORATIQN OE TEEAfi.

ROTARY DRILL CUTTER.

Application filed September l3, 1920.

- the same.

My invention relates to an improvement in rotary cutters adapted for use on rollerearth-boring drills.

In rotary drills adapted for boring wells 5 in earth and rock for water, oil, gas, sulfur, etc, a cutter such ,as is disclosed in connection with this application is "frequently used. This I type of cutter is mounted upon a bearing. which issecured to a pin forming a part of the head of the drilL- The cutter is adapted to rotate upon the hearing, which is preferably formed within a recess in the inner face of the cutter, in such manner that the bearing may not be removed from the rotating cutter. With the hearing thus formed within the cutter, it is necessary to provide a means for holding the cutter and bearing non-rotatably together so that the hearing may be threaded upon the pin to which it is secured. To do this it has been customary to form a radial opening in the cutter which is adapted to index, when in proper position, with a recess in the bearing. Thus by placing a pin through the opening in the cutter and fitting the pin also within the recess in the bearing, the cuttei and bearing together may be rotated to thread the bearing upon the pin. The openinn, through which the wrench or pin is inserted to secure the cutter and bearing together. must, during the operation of the drill. be plugged up by means of a set screw or other similar device. A great deal of ditliculty is ordinarily experienced in getting a set screw which will fit firmly within this opening and which will not be easily removable during the operation of the drill.

An object or" my invention is to provide a means for filling the openingin the out ter. which may be readily applied and which will not he accidentally lost during the op eration of the drill.

Another object is to provide a means for filling the opening in the cutter. which will Serial no. amass.

fit openings of various sizes and which may be removed without diiiiculty, and by means of tools ordinarily to be found about a driiling rig.

Other objects and advantages will appear more clearly in the specification which follows, and the specific details of novelty will be pointed out with particularity in the claims.

Referring to the drawing tor n'iine" a part of this specification, and wherein like numerals of reference are applied to like parts throughout the several views, Fig. 1 is a central longitudinal section through the stub.

shaft or pin, upon which the cutter is mounted, and showing the bearing and cutter attached thereto; Fig. 2 is a transverse section on the line 2 2 of Fig. 1, showing the manher of inserting the wrench; Fig. 3 isa longitudinal section of a plug of compressible material, which is used with my invention; Fig. i is a side elevation of the wrench used in applying myinvention; and Fig. 5 is a broken detail showing a means of. indexing the openings in the cutter and hearing so that the plug may he removed.

iii)

The cutter shown in the drawings is a type of cutter ordinarily used in connection with the bit. shown in the patent to Hughes. No. 1010,406. The improvement is designed for use particularly in connection with the cut-- ter bearing described in my co-pending application No. 410,038,.tlled September 13. 1920. now Patent No. 1,399,856 issued December 13, 1921. This cutter is especially adapted for use in hard material, such as rock. and comprises a roller having a trusteconical forward cutting face. with longitudinal teeth'ti thereon and radial cutting teeth 7 on the truncated forward end to act upon the material. Theinner endof the cutter is beveled inwardly at 8 from the point 9 of largest diameter and toothed at 10 to act upon the side of the hole. The inner end of the cutter has a flat face 11 adapted to bear against the head of the hit. The bearins: l2. upon which this cutter rotates, 1s shaped substantially in the sanie manner tl1erei1ao--raceire-the stuh haftle secured firmly in place.

to the forward end of the head of the drill 'upon which it is mounted. The outer end itll t b h f leis reduced in di m e at 15 to form a furthersupport for the hearing, this reduced shown in the drawing.

A longitudinal oil duct 16 is adapted to conduct the lubricant from the head of the bit through the stub shaft and through a registering channel 17- in the hearing to the inner recess of the cutter.

When it. is desired that this cutter be mounted upon the shaft 14, means is pro vi ded'for securing the cutter and ring non-'rotatably together so thatthe securing of the bearing upon the stub shaft be accomplished. I To do this a radialopening 18 is ordinarily formed in the cutter aiong the largest diameter of the same, this opening being provided with threads or col-' rugations 19 to form a secure'seat for a plug to be inserted therein. The bearing is formed with a plurality of radial recesses Bil. adapted to register with the openings 18 in the cutter. As shown in Fig. 2. these re cesses 20 in the bearing are cut at right angles to each other and it is obviousjhat they may be cut at different angles. and although two recesses only are shown, 1t 1s contemplated that a larger number may be \used if desired.

In mounting this cutter upon the bearing the wrench 21 is inserted into the opening 18 and the cutter is rotated upon the bearing until this opening registers with-one of the recesses 20 in the hearing. The wrench then enters this recess and by means thereof the bearing is rotated so that may be screwed upon the stub shaft 14: and thus secured The wrench 21 is shown in Figs. 2 and 4. It is a straight pin having one end 22 reduced slightly in diameter and rounded for use in securing a plug within the opening 18, aswill be now described.

When the cutter is secured upon the stub shaft. a soft metal plug 23 is then inserted within the opening 18. This plug 23 is cy-r lindrical'l on. its outer surface and its inner end is prdyrded with a'recess 24 somewhat V-shaped tnd formed to fit over the outeredrrc of thebearing 122, with which it is intended to contact, as shown in Fig. 1. This plug also. has'ia rounded recess 25' in the outer end thereof to receive the smaller end 22 of the wrench. When the hearing has been scoured upon the shaft 14, the cutter is rotated slightly so that the opening 18 in the cutter no longer indexes withthe recess 20 in thebcaringr and the plug 23 is then inserted within the opening 18. v The wrench is fitted within the outer recess 25 in the plug and is hammered inwardly against the soft as to drive it laterally metal or the plug so 7 and to completely fill the opening 18 and portion being smooth, as

cured upon the shaft and th readily rec-aces the corrugations of the threadsli therein so that the plug may not be removed during the operation of the cutter. I

lVhen it, is desired to remove the cuttter from the shaft 14-. it will be necessary to drive the soft metal plug inwardly into one of the. recesses 20 in the bearing. To find when the opening 18 registers with the recess 20 a small nail 26. as is shown in Fig. 5, will be driven inwardly through the plug against the hearing. If it strikes the hard metal of thebearing the cutter will be rotatcd until. it is noted that the nail may be driven further into the recess. When the parts have been indexed in this manner. the nail will be withdrawn and the wrench wi l be used as a punch to drive the soft metal plug inwardly. into the recess 20. Tl e wrench may then be inserted into the opering 18 and the cutter may be rotated upon the hearinguntil the wrench registers with another of the recesses 20 in the bcaring.

after which the further wrench and cuttter will ing and unscrew the same from the shaft.

Qrdinarily it is only necessary to unscrew the cutter and bearing from the drill when the teeth are dulled and itis desired to recut the teeth upon the cutter. In order that this operation of driving the plug from the cutter into the bearing may, be accomplished more than once or twice. it will obviously be necessary that more than two openings, or recesses 20 be provided within the hearing, but it is believed, that under ordinary circumstances, two will be sufficient, it being ob /ions that when the cutter has been once removed and repaired it may be again see opening through which it was last inserted may be again filled-with a soft metal plug, in the manner described.

The advantages of this type of means for filling the hole 18 for the wrench will be now understood. The cutter disordinarily shaped'and formed with the teeth thereon while the steel is still soft. The opening 18 is also cut therein while the smells still soft. lWhen properly machined the cutter is then submitted to heat treatment to handen the metal. .This treatment is apt to distort the opening 18 so that a set screw, formed to'fit within this opening, will be found to be either too large ortoo small to accurately fit therein. By the use of a soft metal plug, such as I have described, the use of a set screw may beentirelyavoidcd and a close fit obtained at all times and at the same time the danger of, losing the plug durin the operation of the cutter will be abso utely avoided. As will be apparent, also, this plug applied. It may be inserted and expandedinto position by a few strokes of rotation. of the also rotate the bear:

the hammer, and when it is necessary to remove the same an ordinary nailwill serve sad plug remeee in shah position reietive ii: the heerin 3 the wrench will drive the pi'ug et he the insurer deeerihed.

ihed my invention, whet desire to 'pretect hy Letthe recess "5 cese in said mitt/er, said cutter herring as rediei opening therein at the ielrgeet diameter or said cutter and hearing, e soft metal ph g" ede'pted to fit in seid epeniri said r e cei've expend seid ping edge of mid hearing, med seems to within eeid operi'ng.

2 in e device of the'cherecter described, ev rotatable anther her ing en enierged recess therein, hearing fitting nen-remevehly in recess, said hearing and cutter having rediei openings adapted to register with other, soft metsi ping adapted to fit within the opening in. said cutter, means to and means to thereafter force seid pie, from said cutter into the ogaeiiingin said hearing,

that e few pen I 0 i having e recess in the inner end to re- 3. in a cutter sheit, e hearing havin a three recess for attachment to said s aft, e rote- 80 table cutter on said bearing, said hearing having a, radial recess therein, endsaid cutter having an opening therein with corrugated sides, seid epening being adapted to register "with said recess,'en expansibie me am tel leg to fill said opening and means to exseid piug, end means to thereafter determine when said opening is registered with said recess.

4. In it device of the character described, 40 e rotary cutter of hardened steel, a supporting shaft, e hearing on said shaft, fitting nohremovebiy in said cutter, said cutter having a redial openin therein, a, recess in said bearing registers withseid opening, '45 means to close said opening comprising an expensihle meted pifig, means to register send plug with said recess and means to drive said plug into said recess.

In testimony whereof, I hereunto 'eflix my 50 signature, this the 8th "day of September, A. D, 19520.

i more W. FLETCHER.

e. device of the character described, died 

